International Publication No. WO2015181401 from the same applicant as the current application discloses a joint of a modular blade where the modules are fixed using various bolts between primary and secondary metal inserts. Once each bolt is threaded in its inserts, the bolt must be stressed, taking into account how little space there is between the two blade modules. WO2015181401 discloses various solutions that include both stretching the bolt initially and to maintain this stretching or pre-stressing using spacers placed at intervals.